The present invention relates to a physical uplink channel, and particularly, to transmission of uplink sounding reference signal.
In a coordinated multi-point transmission/reception system (CoMP system), at least two of transmission and reception points cooperate with each other to transmit signals. Such a CoMP system measures an uplink channel state for uplink frequency-dependent schedule and measures an uplink/downlink channel for downlink beam-forming using channel reciprocity. In order to measure the uplink channel state and the uplink/downlink channel, transmission of a sounding reference signal (SRS) is required.